While the design of gas valves has always had the concern of disastrous conditions taking place if leakage occurs, with the advent of extreme product liability and a greater concern for personal safety, there is a continuous endeavor to make gas valves so that when the safety portion of the gas valve closes, gas flow is absolutely terminated. As gas valves of this type generally set for a number of years in an open position, especially if the pilot burner is maintained on throughout the summer, a design for a gas valve to insure that there is an adequate seal should the safety valve close at any time is a necessity.
The present invention is concerned with a dual sealing surface valve to insure adequate termination of gas flow without the expense of two series connected gas valves for redundant safety. Specifically, the valve seating surface and the valve member engage to form two concentric sealing rings or surfaces by having a valve seating surface that has a flat portion and a raised portion concentric of the opening and a flexible valve member which has a flat surface and a raised portion on its outer periphery. When the flexible valve member engages the seating surface, the raised portions engage the respective flat portions to form the two concentric series sealing surfaces to prevent gas flow through the passageway.